JPS61243837A - Cellulose ester film - Google Patents

Abstract

PURPOSE:A cellulose ester film of good strippability and good production efficiency, containing a specified compound. CONSTITUTION:To a dope comprising a solution formed by dissolving 3-50wt% cellulose acetate in an organic solvent (e.g., chloroform) are added 0.1-10wt% compounds of formulas I, II and/or III (wherein R is a 4-22C alkyl, alkenyl or aralkyl, R1 is a 4-16C alkyl, R2 is H or methyl, M is an alkali metal, n1-2 are each 1 or 2, n1+n2=3, n3 is 2-10, n4 is 0-20, n5 is 1-10 and n6 is 2-50). The obtained mixture is heated and filtered. The resulting solution is cast on a drum and stripped from the drum after partial drying. The formed film is further dried to evaporate residual solvent. In this way, the purpose cellulose ester film is obtained.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to cellulose ester films, and in particular, to improving production efficiency in cellulose ester films formed by a casting method by using a stripping aid. This invention relates to a cellulose ester film.

(Prior Art) Cellulose ester films, which are widely used as film supports for photographic light-sensitive materials, polarizing films, etc., are generally made by adding a cellulose ester organic bath solution (referred to as "dope") to metals. It is generally produced by casting on a plastic band, drying it, peeling it off from the band, and drying it again.

In this method of producing cellulose ester film by the so-called casting method, how efficiently it can be produced (that is, at high speed) depends on how quickly the cellulose ester film that is being dried can be peeled off. There is.

For this purpose, various stripping aids have been developed to improve stripping properties.

For example, regarding these stripping and shearing aids, U.S. Patent No. 2. Core 1, No. 7/4, No. 3. ! core.

x33, No. 37 JO4cJ, No. 44J411
.

3 is disclosed in the specification etc.

However, these known stripping aids are not necessarily good stripping aids that can be used industrially.

(Object of the Invention) Therefore, an object of the present invention is to provide a cellulose ester film with good peelability.

(Means for Solving the Problems) The object of the present invention is to solve the problems by
A cellulose ester film characterized in that it contains at least one of the compounds represented by (a).

However, R: an alkyl group having a carbon atom number of C4 to C22,
Alkenyl group, aralkyl group, R□: Alkyl group with number of carbon atoms ~/≦ R2: Hydrogen atom or methyl group M: Alkali metal atom nl, R2: / or Co, n1+n2 3 R3: Co~10 Integer R4: Number of o-xo ns: Integer from / to 10 R6: Number from 2 to 10 If any compound represented by general formula (I), (II) or (III) is a known compound, Representative examples of compounds are as follows.

Compound Example 'Cl8H37-0-P-ONaNa' C□aHas 0-P-ONaNa The amount of these compounds to be used is 0.5% of the dope. /-/']it
L is particularly preferably 0.2-2 weight ratio.

As the cellulose ester used in the present invention, cellulose acetate is preferable, especially the degree of acetylation! t~4.2
1, cellulose acetate is preferred. The cellulose ester in the dope is 3~! O% by weight, especially /! ~2! Preferably, it is a weight sound.

In the present invention, a plasticizer can be added for the purpose of improving the flexibility or moisture resistance of the film.

As the plasticizer, triphenyl 7-phosphate, diethyl 7-thaleate, ethyl phthalylethyl glycolate, methyl 7-talylethyl glycolate, etc. are used. The amount added can range from λ to -20% by weight relative to cellulose triacetate, but the minimum amount that does not impair the flexibility of the membrane is preferred. It is good if the size is between 1 and 2.

Furthermore, various dyes, ultraviolet absorbers, and infrared absorbers may be added alone or in combination for purposes such as optical filters. The amount added varies depending on the purpose of use and is not particularly limited.

In the present invention, examples of the solvent for cellulose triacetate include methylene chloride, chloroform, tetrachloroethyne, dimethylacetoacide, and the like.

The cellulose ester film of the present invention is produced by heating a cellulose ester dope having the composition as described above, filtering it, casting it onto a metal band or drum polished by a Botsper Giesser, and partially drying it (for example, by heating it with jO-%-/JO0C for 7
~75 minutes), then strip it from the band or drum,
Further drying (e.g. at rO~/30°C for ~30 minutes)
and evaporating the remaining solvent.

There are no particular limitations on the method for producing the cellulose ester film according to the present invention, and methods commonly used in the art can be preferably used.

Regarding the manufacturing method of cellulose ester film, for example, U.S. Patent Nos. λ41.2-7, U.S. Pat. No., No. 2 ≠ Takotough No., No. 2 t.

No. 770, British Patent No. 64I07J/, British Patent No. 7sz
rter, special public Akihiro j-ta 07u publication, same≠2-1j
It is possible to refer to the descriptions in Publication No. J, Publication No. 1 of Kota Zti≠, and the like.

A particularly preferred example of the method for producing the cellulose triacetate film of the present invention is as follows.

That is, cellulose triacetate (bond acetylation degree jt-4
2% (preferably 19% or more)) to methylene chloride.
Dissolve ~jOwt%, preferably lj~Cojwt%,
The obtained solution is 100-/100C, preferably 120~
It is heated to 760°C and cast onto a support from a casting die to a thickness of lO0~13o0c, preferably lO~/2j.
Dry at 0C with a residual volatile content of 20.10%, preferably 7.
When the temperature reaches 2~1J, peel it off at 17°C-≠0C1.
Preferably, it is rapidly cooled with cold air at O'C-2°C. After cooling as it is for 30 seconds or more, residual volatile matter is removed at RO 0C to obtain a completed film.

Further explanation will be given below with reference to Examples.

Example-1 Acetyl cellulose 70%
0 parts of a mixed solvent of methylene chloride and methanol <9
0/10) a4/lo part Kl was mixed and dissolved at O0C, and 1 part of triphenyl 7 phosphate and the additives shown in Table 1 were added to make a completely homogeneous solution.

The aqueous solution was kept at izo 0c, filtered, and cast onto a support with a liquid film thickness (7, r-2 mm) using a casting die.
The support was dried for 30 minutes with a hot dryer and peeled off. The peeling resistance at this time was measured using a spring meter.

The results obtained are shown in Table 7.

The peeled film was quenched for o'ci minutes, then t
The final film was dried for 00 minutes.

As is clear from Table 1, the cellulose acetate film according to the present invention has low peeling resistance and is excellent in high-speed casting suitability.

Claims (1)

[Scope of Claims] A cellulose ester film containing at least one compound represented by the general formula (I), (II) or (III). (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ However, R: Alkyl with a carbon atom number of C_4 to C_2_2 group, alkenyl group, aralkyl group, R_1: alkyl group having 4 to 16 carbon atoms R_2: hydrogen atom or methyl group M: alkali metal atom n_1, n_2: 1 or 2, n_1+n_2=3 n_3: 2 to 10 Integer n_4: Number of 0 to 20 n_5: Integer of 1 to 10 n_6: Number of 2 to 50